The clinical core is responsible for ascertainment of new target patients, maintenance of the current registry, identification and examination of survivors of two previously established cohorts, recruitment of normal young and elderly Chamorros, clinical examinations, autopsies, collection of blood and CSF specimens and storage, and shipment of specimens to New York (Core C), Seattle (Project 3), and Philadelphia (Project 4). Besides providing excellent clinical characterization of patients and normal controls, Core B. either directly or indirectly, contributes specifically to Core C and all projects. The overall administration will be located at UCSD in San Diego and the Gleam research team will be located at the University of Guam. Dr. Ulla Craig will coordinate all activities on Guam unda the supervision of the principal investigator. New potential target cases will be identified through a screening system of all major health care provides, nursing homes, public health department, and each village mayor's office. Autopsies will be performed at Guam Memorial Hospital, in the Chief Medical Examiner's office, and at the Navy Hospital. Except for the necrologic examinations of patients and normal subjects, all other examinations will be performed by professional staff fluent in Chamorro. Neurologic examinations will be done by board certified neurologists, including the principal investigator, who will spend additional time on the island to supervise all activities and for liaison purposes to health care providers, public health department, University of Guam staff and government offices.